Archived posting to the Leica Users Group, 1999/04/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi, Luggers interested in Cosina lenses. Cosina publishes MTF charts for the two LTM lenses. Since I cannot find any web sites showing them, I list some of the values. 15 mm at f4.5/infinity (0mm, 10mm, 20mm from center) (10 lp/mm) 0.98/0.98, 0.95/0.92, 0.9/0.8 (20 lp/mm) 0.92/0.92, 0.88/0.8, 0.8/0.5 (40 lp/mm) 0.85/0.85, 0.7/0.55, 0.6/0.3 No significant increases at f8. These values are close to those of Hologon 16/8 for Contax G. 25 mm at f 4/infinity (0mm, 10mm, 20mm from center) (10 lp/mm) 0.96/0.96, 0.92/0.92, 0.85/0.75 (20 lp/mm) 0.9/0.9, 0.85/0.85, 0.6/0.7 (40 lp/mm) 0.8/0.8, 0.6/0.65, 0.45/0.4 At f8, contrast values for 20 and 40 lp/mm somewhat increase in the periphery. Of course, MTF is not everything. ;-) Mikiro Strasbourg